<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2012 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: ZhangXuehun <zhangxuehun@sohu.com>
// +----------------------------------------------------------------------
// $Id: DbOracle.class.php 2729 2012-02-12 04:13:34Z liu21st $

/**
 +------------------------------
 * Oracle数据库驱动类
 +------------------------------
 */
class DbOracle extends Db{

	private $mode = OCI_COMMIT_ON_SUCCESS;
	private $table  =  '';
	protected $selectSql  =     'SELECT * FROM (SELECT thinkphp.*, rownum AS numrow FROM (SELECT  %DISTINCT% %FIELD% FROM %TABLE%%JOIN%%WHERE%%GROUP%%HAVING%%ORDER%) thinkphp ) %LIMIT%';

	/**
	 +----------------------------------------------------------
	 * 架构函数 读取数据库配置信息
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @param array $config 数据库配置数组
	 +----------------------------------------------------------
	 */
	public function __construct($config=''){
		putenv("NLS_LANG=AMERICAN_AMERICA.UTF8");
		if ( !extension_loaded('oci8') ) {
			throw_exception(L('_NOT_SUPPERT_').'oracle');
		}
		if(!empty($config)) {
			$this->config        =        $config;
			if(empty($this->config['params'])) {
				$this->config['params'] =   array();
			}
		}
	}

	/**
	 +----------------------------------------------------------
	 * 连接数据库方法
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function connect($config='',$linkNum=0) {
		if ( !isset($this->linkID[$linkNum]) ) {
			if(empty($config))  $config = $this->config;
			$pconnect   = !empty($config['params']['persist'])? $config['params']['persist']:$this->pconnect;
			$conn = $pconnect ? 'oci_pconnect':'oci_new_connect';
			$this->linkID[$linkNum] = $conn($config['username'], $config['password'],$config['database']);//modify by wyfeng at 2008.12.19

			if (!$this->linkID[$linkNum]){
				$error = $this->error(false);
				throw_exception($error["message"], '', $error["code"]);
			}
			// 标记连接成功
			$this->connected = true;
			//注销数据库安全信息
			if(1 != C('DB_DEPLOY_TYPE')) unset($this->config);
		}
		return $this->linkID[$linkNum];
	}

	/**
	 +----------------------------------------------------------
	 * 释放查询结果
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 */
	public function free() {
		oci_free_statement($this->queryID);
		$this->queryID = null;
	}

	/**
	 +----------------------------------------------------------
	 * 执行查询 返回数据集
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @param string $str  sql指令
	 +----------------------------------------------------------
	 * @return mixed
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function query($str) {
		$this->initConnect(false);
		if ( !$this->_linkID ) return false;
		$this->queryStr = $str;
		//更改事务模式
		$this->mode = OCI_COMMIT_ON_SUCCESS;
		//释放前次的查询结果
		if ( $this->queryID ) $this->free();
		N('db_query',1);
		// 记录开始执行时间
		G('queryStartTime');
		$this->queryID = oci_parse($this->_linkID,$str);
		$this->debug();
		if (false === oci_execute($this->queryID, $this->mode)) {
			$this->error();
			return false;
		} else {
			return $this->getAll();
		}
	}

	/**
	 +----------------------------------------------------------
	 * 执行语句
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @param string $str  sql指令
	 +----------------------------------------------------------
	 * @return integer
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function execute($str) {
		$this->initConnect(true);
		if ( !$this->_linkID ) return false;
		$this->queryStr = $str;
		// 判断新增操作
		$flag = false;
		if(preg_match("/^\s*(INSERT\s+INTO)\s+(\w+)\s+/i", $this->queryStr, $match)) {
			$this->table = C("DB_SEQUENCE_PREFIX") .str_ireplace(C("DB_PREFIX"), "", $match[2]);
			$flag = (boolean)$this->query("SELECT * FROM user_sequences WHERE sequence_name='" . strtoupper($this->table) . "'");
		}//modify by wyfeng at 2009.08.28

		//更改事务模式
		$this->mode = OCI_COMMIT_ON_SUCCESS;
		//释放前次的查询结果
		if ( $this->queryID ) $this->free();
		N('db_write',1);
		// 记录开始执行时间
		G('queryStartTime');
		$stmt = oci_parse($this->_linkID,$str);
		$this->debug();
		if (false === oci_execute($stmt)) {
			$this->error();
			return false;
		} else {
			$this->numRows = oci_num_rows($stmt);
			$this->lastInsID = $flag?$this->insertLastId():0;//modify by wyfeng at 2009.08.28
			return $this->numRows;
		}
	}

	/**
	 +----------------------------------------------------------
	 * 启动事务
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return void
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function startTrans() {
		$this->initConnect(true);
		if ( !$this->_linkID ) return false;
		//数据rollback 支持
		if ($this->transTimes == 0) {
			$this->mode = OCI_DEFAULT;
		}
		$this->transTimes++;
		return ;
	}

	/**
	 +----------------------------------------------------------
	 * 用于非自动提交状态下面的查询提交
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return boolen
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function commit(){
		if ($this->transTimes > 0) {
			$result = oci_commit($this->_linkID);
			if(!$result){
				throw_exception($this->error());
			}
			$this->transTimes = 0;
		}
		return true;
	}

	/**
	 +----------------------------------------------------------
	 * 事务回滚
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return boolen
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function rollback(){
		if ($this->transTimes > 0) {
			$result = oci_rollback($this->_linkID);
			if(!$result){
				throw_exception($this->error());
			}
			$this->transTimes = 0;
		}
		return true;
	}

	/**
	 +----------------------------------------------------------
	 * 获得所有的查询数据
	 +----------------------------------------------------------
	 * @access private
	 +----------------------------------------------------------
	 * @return array
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	private function getAll() {
		//返回数据集
		$result = array();
		$this->numRows = oci_fetch_all($this->queryID, $result, 0, -1, OCI_FETCHSTATEMENT_BY_ROW);
		//add by wyfeng at 2008-12-23 强制将字段名转换为小写，以配合Model类函数如count等
		if(C("DB_CASE_LOWER")) {
			foreach($result as $k=>$v) {
				$result[$k] = array_change_key_case($result[$k], CASE_LOWER);
			}
		}
		return $result;
	}


	/**
	 +----------------------------------------------------------
	 * 取得数据表的字段信息
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function getFields($tableName) {
		$result = $this->query("select a.column_name,data_type,decode(nullable,'Y',0,1) notnull,data_default,decode(a.column_name,b.column_name,1,0) pk "
		."from user_tab_columns a,(select column_name from user_constraints c,user_cons_columns col "
		."where c.constraint_name=col.constraint_name and c.constraint_type='P'and c.table_name='".strtoupper($tableName)
		."') b where table_name='".strtoupper($tableName)."' and a.column_name=b.column_name(+)");
		$info   =   array();
		if($result) {
			foreach ($result as $key => $val) {
				$info[strtolower($val['column_name'])] = array(
                    'name'    => strtolower($val['column_name']),
                    'type'    => strtolower($val['data_type']),
                    'notnull' => $val['notnull'],
                    'default' => $val['data_default'],
                    'primary' => $val['pk'],
                    'autoinc' => $val['pk'],
				);
			}
		}
		return $info;
	}

	/**
	 +----------------------------------------------------------
	 * 取得数据库的表信息（暂时实现取得用户表信息）
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function getTables($dbName='') {
		$result = $this->query("select table_name from user_tables");
		$info   =   array();
		foreach ($result as $key => $val) {
			$info[$key] = current($val);
		}
		return $info;
	}

	/**
	 +----------------------------------------------------------
	 * 关闭数据库
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 */
	public function close() {
		if($this->_linkID){
			oci_close($this->_linkID);
		}
		$this->_linkID = null;
	}

	/**
	 +----------------------------------------------------------
	 * 数据库错误信息
	 * 并显示当前的SQL语句
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return string
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function error($result = true) {
		if($result){
			$this->error = oci_error($this->queryID);
		}elseif(!$this->_linkID){
			$this->error = oci_error();
		}else{
			$this->error = oci_error($this->_linkID);
		}
		if($this->debug && '' != $this->queryStr){
			$this->error .= "\n [ SQL语句 ] : ".$this->queryStr;
		}
		return $this->error;
	}

	/**
	 +----------------------------------------------------------
	 * SQL指令安全过滤
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @param mix $str  SQL指令
	 +----------------------------------------------------------
	 * @return string
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function escapeString($str) {
		return str_ireplace("'", "''", $str);
	}

	/**
	 +----------------------------------------------------------
	 * 获取最后插入id ,仅适用于采用序列+触发器结合生成ID的方式
	 * 在config.php中指定
	 'DB_TRIGGER_PREFIX'	=>	'tr_',
	 'DB_SEQUENCE_PREFIX' =>	'ts_',
	 * eg:表 tb_user
	 相对tb_user的序列为：
	 -- Create sequence
	 create sequence TS_USER
	 minvalue 1
	 maxvalue 999999999999999999999999999
	 start with 1
	 increment by 1
	 nocache;
	 相对tb_user,ts_user的触发器为：
	 create or replace trigger TR_USER
	 before insert on "TB_USER"
	 for each row
	 begin
	 select "TS_USER".nextval into :NEW.ID from dual;
	 end;
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return integer
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function insertLastId() {
		if(empty($this->table)) {
			return 0;
		}
		$sequenceName = $this->table;
		$vo = $this->query("SELECT {$sequenceName}.currval currval FROM dual");
		return $vo?$vo[0]["currval"]:0;
	}

	/**
	 +----------------------------------------------------------
	 * limit
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return string
	 +----------------------------------------------------------
	 */
	public function parseLimit($limit) {
		$limitStr    = '';
		if(!empty($limit)) {
			$limit	=	explode(',',$limit);
			if(count($limit)>1)
			$limitStr = "(numrow>" . $limit[0] . ") AND (numrow<=" . ($limit[0]+$limit[1]) . ")";
			else
			$limitStr = "(numrow>0 AND numrow<=".$limit[0].")";
		}
		return $limitStr?' WHERE '.$limitStr:'';
	}
}